Valved connector assembly and sterility barriers for heat exchange catheters and other closed loop catheters

ABSTRACT

A connector assembly for catheters having closed loop flow circuits, such as some balloon catheters and heat exchange catheters. The connector assembly comprises first and second connector bodies that may be connected and disconnected from one another. When the connector bodies are disconnected, a syringe or negative pressure source may be attached to withdraw residual fluid from the catheter&#39;s closed loop circuit and to deflate any expandable portion of the closed loop circuit (e.g., balloon or expandable heat exchanger). A one way flow valve prevents make up air or other fluid from entering the catheter while the negative pressure is being applied. Also disclosed are sterility barrier assemblies for all types of catheters. Such sterility barrier assemblies are operative to prevent contamination of the portion of a catheter that remains outside of a patient&#39;s body so that the catheter may subsequently be further advanced into the patient&#39;s body without introducing microbes or other contaminants into the patient&#39;s body.

RELATED APPLICATIONS

This is a continuation of copending U.S. patent application Ser. No.11/061,803 filed Feb. 17, 2005, which is a continuation of U.S. patentapplication Ser. No. 10/273,637 filed Oct. 18, 2002 now issued as U.S.Pat. No. 6,887,263, the entire disclosures of such applications beingexpressly incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates generally to devices and methods for medicaltreatment and more particularly to catheters that are insertable intothe bodies of human or veterinary patients and related methods.

BACKGROUND OF THE INVENTION

A. Closed Loop Catheters

The prior art has included numerous “closed loop” catheters havingclosed loop fluid flow circuits formed within the catheter. Examples ofsuch closed loop catheters include various types of catheters that havea) a first lumen through which a fluid may flow into the catheter bodyand b) a second lumen through which fluid that has entered the catheterbody through the first lumen may subsequently flow out of the catheterbody. In some instances, a reservoir (e.g., chamber, vesicle, collector,space, etc.) may be formed on or within the catheter in fluidcommunication with the first and second lumens such that fluid infusedthrough the first lumen may collect within the reservoir and maysubsequently flow out of the reservoir through the second lumen. Also,in some instances, the reservoir may have one or more flexible wall(s)and may be inflatable such that the reservoir expands when filled withfluid and collapses when fluid is evacuated from the reservoir. Examplesof expandable reservoirs include various types of balloons includingthose which are elastic as well as those that are non-compliant and/orheat exchangers that may be formed on or in a catheter.

One specific type of closed loop catheter is an endovascular heatexchange catheter that may be inserted into a patient's blood vessel andused to heat or cool the blood flowing through that blood vessel and,hence, all or a portion of the patient's body. In these endovascularheat exchange catheters heated or cooled heat transfer fluid (e.g.,saline solution) is circulated though a closed loop circuit. The closedloop circuit may include an expandable (e.g., inflatable) heat exchanger(e.g., a heat exchange balloon) that has a collapsed configuration whenuninflated and an expanded configuration when inflated. Typically,endovascular heat exchange catheters that have expandable (e.g.,inflatable) heat exchangers are inserted into the patient's vasculaturethrough a small introducer or puncture tract while the heat exchanger isin its collapsed (e.g., uninflated) configuration. Thereafter, heattransfer fluid is circulated through the heat exchanger, causing it toassume its expanded (e.g., inflated) configuration. After the procedurehas been completed, it is generally desirable to fully deflate the heatexchanger before attempting to reposition or remove heat exchangecatheter from the patient's body to facilitate its passage through therelatively small diameter introducer/puncture site and to avoid possibledamage to the patient's blood vessels. To accomplish such deflation ofthe heat exchanger, it may be desirable to apply negative pressure tothe fluid lumen(s) of the catheter to ensure that the heat exchanger isfully deflated and in its fully collapsed configuration. Examples ofsuch endovascular heat exchange catheters and related apparatus includethose described in U.S. Pat. No. 5,486,208 (Ginsburg), PCT InternationalPublication WO OO/10494 (Machold et al.), U.S. Pat. No. 6,264,679(Keller et al.), PCT International Publication Nos. WO-00/10494 (RadiantMedical, Inc.) and WO 01/58397 (Radiant Medical, Inc.), all of which areexpressly incorporated herein by reference.

There also exist various other types of “closed loop” catheters thathave inflatable balloons or fluid-expandable members that must be fullydeflated prior to movement or removal of the catheter from the body.Especially in cases where the balloon or fluid-expandable member isinflatable or expandable but not elastic, it may be desirable or evennecessary to apply negative pressure to the catheter lumen(s) to fullydeflate the balloon or fluid-expandable member to ensure its completecollapse before moving or removing the catheter from the body.

B. Sterility Barriers for Medical Catheters:

After any catheter has been inserted into a patient's vasculature, it issometimes desirable to further advance or reposition the catheter. If aproximal portion of the catheter has become exposed to room air andpossible microbial contamination, further advancement of that portion ofthe catheter into the patient's vasculature may risk introduction ofmicrobial contamination into the patient's blood. Thus, the prior arthas included various apparatus and methods for creating sterilitybarriers to prevent contamination of patients and/or medical devices,including those apparatus and methods described in U.S. Pat. Nos.5,385,495 (Lynn), 5,775,328 (Lowe et al.), 4,491,137 (Jingu), 4,646,772(Silverstein et al.), 4,898,178 (Wedel), 5,341,810 (Dardel), 5,490,522(Dardel), 5,498,230 (Adair) and PCT International Publication Nos.WO84/03034 (Drue et al.), WO97/49337 (Loxe et al.) And WO99/48424 (Loweet al.).

Notwithstanding the prior art, there remains a need in the art for thedevelopment of new connectors for closed loop catheters to facilitateand verify complete evacuation of fluid from those catheter's closedloop fluid flow circuits and complete deflation of any expandablereservoirs (e.g., heat exchangers, balloons, etc.) formed in or on thoseclosed loop catheters. Separately or in combination with such newconnectors, there also remains a need in the art for the development ofimproved sterility barriers for maintaining sterility of theexteriorized portions of catheters that may be further advanced into thepatient's body at a later time.

SUMMARY OF THE INVENTION

The present invention provides a closed loop catheter device thatcomprises (a) an elongate, flexible catheter body having a proximal endand a distal end, (b) a closed loop fluid flow circuit comprising afirst lumen through which a fluid may flow into the catheter body and asecond lumen through which fluid that has entered the catheter bodythrough the first lumen may subsequently flow out of the catheter body,(c) a connector assembly on the proximal end of the catheter body, suchconnector being having an inflow lumen which is connectable to anddisconnectable from an inflow fluid source and an outflow lumen which isconnectable and disconnectable from an outflow fluid receiver into whichfluid may flow out of the first lumen and, (d) a valving apparatus whichcloses at least one of the first and second lumens when the connector isdisconnected from at least the inflow source such that fluid may then beevacuated from the closed loop circuit through the lumen that remainsunclosed without concurrent entry of make-up air or other fluid into theclosed loop circuit though the lumen that has been closed by the valvingapparatus. Additionally, the closed loop circuit may incorporate areservoir (e.g., a cavity, vessel, void, balloon, heat exchanger,compliant balloon, bag or expandable/inflatable region) between thefirst and second lumens. After the connector has been disconnected,negative pressure (e.g., suction) may be applied to the other lumen(e.g., the lumen that remains open to flow in the outward direction) toevacuate remaining fluid from the reservoir without re-entry of make-upair or make-up fluid into the reservoir through the closed lumen. Inembodiments where the reservoir is expandable (e.g., a radiallyexpandable balloon or heat exchanger), this procedure may be used tofully collapse (e.g., deflate) the reservoir (e.g., balloon or heatexchanger) prior to withdrawal or repositioning of the catheter. In someembodiments pressure indicating apparatus may be provided to indicatewhen the pressure within the closed loop circuit has fallen below acertain predetermined pressure and, accordingly, any expandablereservoir has been sufficiently deflated or collapsed to allow thecatheter to be safely moved or withdrawn from the patient's body. Also,in some embodiments of the invention, the catheter may comprise a heatexchange catheter wherein the closed loop circuit and/or the reservoircomprise a heat exchanger and the fluid that is circulated through theclosed loop circuit (and if present, the reservoir) comprises a heattransfer fluid such as saline solution, water or any other suitablefluid capable of being heated or cooled. Such heat exchange cathetersmay be used to warm or cool all or a portion of a patient's body. Insome embodiments, the heat exchanger may comprise an expandablereservoir which expands and contracts in relation to the pressure offluid within the heat exchanger. In such embodiments, the connectorassembly of the present invention will facilitate rapid connection anddisconnection of the catheter from its source of heat transfer fluid andwill also provide a convenient means for attaching a deflation apparatus(e.g., a syringe) to extract remaining fluid from the closed loop flowcircuit after the catheter has been disconnected from its source of heattransfer fluid.

Further in accordance with the present invention, there is provided asterility barrier that is useable on virtually any type of catheter thatis insertable into the body of a human or veterinary patient, suchsterility barrier is configured to substantially surround anexteriorized portion of the catheter so as to substantially preventcontamination of the exteriorized portion of the catheter by microbes,dirt, chemical substances, etc. If it is subsequently desired to advancethe catheter further into the patient's body, all of some of theexteriorized portion that has been substantially surrounded by thesterility barrier will be free of contamination and may be advanced intothe patient's body without undo risk of infection or other untowardconsequences that could result from introduction of a contaminatedsection of catheter into the patient's body. The sterility barrier maybe generally tube-shaped and may be formed of thin, flexible plasticfilm. The sterility barrier may be transparent to allow visualization ofthe exteriorized portion of the catheter through the sterility barrier.Length markings may be formed on the exteriorized portion of thecatheter to allow an operator to determine the length of catheter thatresides within the patient's body at any given point in time. In someembodiments, a proximal hub member may be attached to a proximal end ofthe catheter and a distal hub member may be positioned distal to theproximal hub member with the body of the catheter being slidablyadvancable through the distal hub member. The sterility barrier may beaffixed and sealed to the proximal and distal hub members and one orboth of the proximal and distal hub members may be affixable to thepatient's body (e.g, the hub member(s) may be taped to the patient'sskin). In this manner, an exteriorized portion of catheter extendingbetween the proximal and distal hub members will be substantiallysurrounded and shielded by the sterility barrier and some or all of suchexteriorized portion may be subsequently advanced through the distal hubmember and into the patient's body.

Further aspects and advantages of the present invention will berecognized and understood by those of skill in the art upon reading ofthe detailed description and examples of the invention set forthherebelow and in the accompanying drawings.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a closed catheter of the presentinvention having a connector assembly of the present invention on theproximal end of the catheter as well as a sterility barrier of thepresent invention for preventing microbial contamination of anexteriorized proximal portion of the catheter.

FIG. 1A is an exploded view of the connector assembly and sterilitybarrier components of the catheter of FIG. 1.

FIG. 2 is a perspective view of one type of automated endovascular heatexchange system incorporating a heat exchange catheter that includes aconnector assembly of the present invention on the proximal end of thecatheter as well as a sterility barrier of the present invention forpreventing microbial contamination of an exteriorized proximal portionof the catheter.

FIGS. 3A-3C show in step-by-step fashion a method by which a sterilitybarrier assembly of the present invention may be used to microbialcontamination of an exteriorized proximal portion of the catheter and tofacilitate advancement or repositioning of the catheter subsequent toits initial insertion into a patient's body.

FIGS. 4A-4C show in step-by-step fashion a method by which a connectorassembly of the present invention may be used to accomplishdisconnection of a closed loop catheter from a fluid source andsubsequent evacuation of residual fluid from the catheter's closed loopfluid flow circuit.

FIG. 5 is a side elevational view of the heat exchange cathetercomponent of the automated endovascular heat exchange system of FIG. 2.

FIG. 5A is a cross-sectional view through line 5A-5A of FIG. 5.

FIG. 5B is a cross-sectional view through line 5B-5B of FIG. 5.

FIG. 5C is a cross-sectional view through line 5C-5C of FIG. 5.

FIG. 5D is a cross-sectional view through line 5D-5D of FIG. 5.

FIG. 6 is an enlarged, perspective view of the portion of the heatexchange catheter within circle 6 of FIG. 5.

FIG. 7 is an enlarged, perspective view of the portion of the heatexchange catheter within circle 7 of FIG. 5.

DETAILED DESCRIPTION A. A Valved Connector & Sterility Barrier Assembly

Components and Construction of the Connector & Sterility BarrierAssembly

FIGS. 1-4 c show an example of a valved connector and sterility barrierassembly 10 of this invention attached to one type of closed loop heatexchange catheter 260. The valved connector and sterility barrierassembly 10 comprises a connector portion 11 and a sterility barrierportion 19 which, although shown in combination in this example, may beprovided and/or used separately as well.

The connector portion 11 includes a) a first connector body 12 that isattached to or formed on the ends of a fluid inflow source such as afluid inflow tube 297 and a fluid outflow receptacle such as a fluidoutflow tube 299, b) a second connector body 14 that is connectable tothe first connector body 12, c) latches 16 for deterring inadvertentseparation or disconnection of the first and second connector bodies 12and 14 respectively, and d) a catheter inflow feed tube 18 and catheteroutflow receiving tube 20. The sterility barrier portion 19 includes a)a proximal hub member 22, b) a distal hub member 24 and c) a generallytubular sterility barrier sleeve 26 that is affixed to and extendsbetween the proximal hub member 22 and the distal hub member 24. In thisexample, the connector and sterility barrier assembly 10 is shown inconjunction with a heat exchange catheter device 260. The particularheat exchange catheter device 260 of this example generally comprises anelongate, flexible catheter body 264 and an expandable/collapsible heatexchanger 268 positioned on the distal end of the catheter body 264.Details of this particular heat exchange catheter device 260 are shownin FIGS. 5-7 and are described in further detail herebelow.

The connector portion 11 of the assembly 10 functions to permit thecatheter 260 to be rapidly connected and disconnected to an inflow fluidsource (such as inflow tube 297) and an outflow fluid receptacle (suchas an outflow tube 299). Thus, heated or cooled heat transfer fluid maybe circulated through the catheter body 264 and heat exchanger 268. Thisconnector portion 11 of the assembly 10 also facilitates completedeflation and contraction or collapse of the heat exchanger 268following completion of a patient treatment procedure, thereby ensuringthat the heat exchanger is fully collapsed (i.e., fully reduced indiameter) before the catheter 260 is moved or withdrawn from thepatient's body.

The sterility barrier portion 19 of the assembly 10 functions tosubstantially encapsulate and deter microbial or other contamination ofthat portion of the catheter body 264 that is, at that point in time,positioned between the proximal hub member 22 and the distal hub member24.

Certain details of the construction of the connector & sterility barrierassembly 10 may be appreciated from the exploded view of FIG. 1A and theperspective showing of FIG. 4 a. As shown in this example, the firstconnector body 12 comprises a rigid body which has inflow and outflowlumens or bores extending longitudinally therethrough. The distalportion 12 d of the first connector body 12 is enlarged and thediameters of the inflow and outflow bores are greater in the distalportion 12 d than in the proximal portion 12 p of the first connectorbody 12. Annular shoulders or step-downs 51 are thus formed in the wallsof the inflow and outflow bores of the first connector body 12, therebydefining enlarged distal bores 43, 49 of the bores which are openthrough the distal end of the first connector body 12. This firstconnector body 12 may be attached to or formed on the ends of fluidinflow 297 and fluid outflow 299 tubes such that the fluid inflow willpass through one bore of the first connector body 12 and the fluidoutflow will pass through the other bore of the first connector body 12.As will be appreciated from FIG. 2 (and the description of FIG. 2provided herebelow) the inflow tube 297 and outflow tube 299 may be inthe form of separate tubes or may comprise separate lumens within amulti-lumen flow conduit 265. First latch components comprising pawls 16a are attached to or formed on the first connector body 12, as shown.

The second connector body 14 also comprises a rigid body that has inflowand outflow lumens or bores extending longitudinally therethrough.Second latch components comprising pawl-receiving notches or depressions16 b are formed on the top and bottom surfaces of the second connectorbody 14. Male tubular projections 42, 48 extend from the proximal end ofthe second connector body 14. One male tubular projection 48 iscontinuous with the inflow bore of the second connector body 14 andanother male tubular projection 42 is continuous with the outflow boreof the second connector body 14. O rings 53 a, 53 b are seated withingrooves formed about the tubular projections 42, 48. A one way valve 46,such as a duckbill valve or other suitable type of check valve known inthe art, is mounted within the outflow bore of the second connector body14. In some embodiments, the one way valve 46 may operate continuouslyto block flow in the inflow direction through the outflow boreirrespective of whether or not the first connector body 12 is connectedto the second connector body 14. However, in other embodiments, the oneway valve may become activated such that it blocks flow in at least theinflow direction through the outflow bore of the second connector body14 only when the first connector body 12 is separated from the secondconnector body 14. For example, a projection (not shown) may extend inthe distal direction from the outflow side of the first connector body12 such that it becomes inserted into the outflow bore of the secondconnector body 14 when the first and second connector bodies 12 and 14are placed in their joined or connected positions (FIG. 1) and one ormore hinged or flexible valve leaflets or moveable bulkheads may bedisposed within the outflow bore of the second connector body 14 suchthat such projection will force the hinged or flexible valve leaflets ormoveable bulkheads to an open position when the first and secondconnector bodies 12, 14 are placed in their connected or joinedpositions (thereby allowing flow in both directions through the outflowbore of the second connector body 14) and the hinged or flexible valveleaflets will spring closed or otherwise become closed when the firstand second connector bodies 12, 14 become separated from one another(thereby preventing flow in at least the inflow direction through theoutflow bore of the second connector body).

Inflow feed tube 18 and outflow feed tube 20 extend through a rigidguide member 50 and are attached to the distal end of the secondconnector body 14 to connect its inflow and outflow bores to thecatheter body 264.

When the first connector body 12 and second connector body 14 areconnected to one another, the male tubular projections 42, 48 arereceived within the enlarged distal portions 43, 49 of the bores of thefirst connector body 12 until the ends of the male projections 42, 48abut against the annular shoulders 51 formed in the walls of the firstconnector body's bores. The pawls 16 a of the first connector body 12are inwardly biased such that they snap fit into the correspondingnotches 16 b in the second connector body 14, thereby holding the firstconnector body 12 and second connector body 14 in connection with oneanother. When it is desired to disconnect the connector bodies 12, 14,the proximal ends of the paws 16 a are depressed causing the distal endsof the pawls 16 a to lift out of notches 16 b and the proximal connecterbody 12 is pulled away and separated from the distal connector body 14.

After the connector bodies 12, 14 have been separated, a syringe SYR orother source of negative pressure may be attached to tubular projection48 and used draw residual fluid out of the catheter body 264 and heatexchanger 268, thereby causing heat exchanger 268 to assume a collapsedconfiguration in which the diameter of the heat exchanger 268 is onlyslightly larger than the diameter of the catheter body 264 adjacent tothe heat exchanger 268. The one way valve 46 prevents air from enteringthe catheter body 264 or heat exchanger 268 during this deflationprocess, thus ensuring that the heat exchanger may be fully collapsed.

An optional pressure indicator 57 may provide an indication of thepressure within the catheter's closed loop circuit or at least anindication of when the pressure within the closed loop circuit issufficiently low or negative to ensure that the heat exchanger has beencollapsed to a diameter that would allow the catheter 260 to be moved orwithdrawn from the body without hanging up on the introducer throughwhich the catheter 260 is inserted and without causing trauma to thepatient's vasculature. This optional pressure indicating apparatus maycomprise any suitable type of pressure indication, including a simpledome made of plastic that inverts to form a dimple when the pressurewithin the closed loop circuit is sufficiently negative to ensureadequate deflation of the heat exchanger (or any other expandable itemon the catheter, such as a balloon). In some embodiments, there may alsobe an optional disabling apparatus that renders the catheternon-reusable after the fluid has been evacuated from the closed loopflow circuit. This will deter unauthorized reuse of a previously usedcatheter 260. In this regard, in embodiments having a pressure indicatorthat inverts or dimples inward in response to negative pressure withinthe closed loop circuit, such apparatus my comprise or include a lumenblocker or bulkhead that would prevent subsequent flow of fluid throughthe closed loop circuit one the heat exchanger 268 (or balloon or otherexpandable aspect of the catheter 260) has been deflated by applicationof negative pressure.

The sterility barrier assembly can also be appreciated from the showingof FIG. 1 a. As shown, the proximal hub member 22 and distal hub member24 may be provided with laterally extending wings or otherwiseconfigured so as to facilitate taping of the hub members 22, 24 to thepatient's skin. The sterility barrier sleeve 26 may comprise a tubeformed of clear, flexible plastic film having a thickness in the rangeof about 0.5 mills to about 10 mills, and preferably approximately 2mills. Distance interval markings 27 may be formed on a proximal portionof the catheter body 264 to provide visual indicia of the length ofcatheter body 264 that has been advanced through the distal hub member24 relative to the length of catheter body 264 that remains within thesterility barrier 264.

Method of Use of the Connector & Sterility Barrier Assembly

A method for using the connector & sterility barrier assembly 10 isshown in FIGS. 3 a-3 c and 4 a-4 c. As shown, the catheter 260 istypically inserted into the patient's vasculature using a Seldingertechnique wherein a tubular introducer sheath 40 is inserted into ablood vessel BV and the catheter body 264 is then advanced through theintroducer 40 and into the blood vessel BV. The catheter body 264 maythen be advanced through the vasculature until the heat exchanger 268 isat the desired position. The tubular distal portion of the distal hubmember 24 may be received within the hub of the introducer 40, as shownin FIG. 3 a. In some embodiments, the hub of the introducer 40 may becustom made to mate with the distal portion of the distal hub member 24so that the hub member 24 may snap fit, bayonet lock or otherwise form acontamination proof seal and/or locking connection with the hub of theintroducer 40. The catheter body 264 remains slidably advanceable andretractable through the distal hub member 24 and introducer 40. In somecases the distal hub member 24 may not actually inserted into the hub ofthe introducer 40, but may remain a spaced distance behind the hub ofthe introducer 40. In ether case, the distal aspect of the distal hubmember 24, the hub of the introducer 40 and any portion of the catheterbody 264 exposed therebetween may optionally be covered with a steriledressing as is common in the art, thereby further deterring microbial orother contamination of the exteriorized portion of the catheter body264. The remainder of the exteriorized portion of the catheter bodyresides between the hub members 22, 24 and is protected fromcontamination by the sterility barrier sleeve 26. As shown in FIGS. 3b-3 c, when it is desired to further advance the catheter body 264 intothe patient, the operator may grasp the catheter body 264 through thesterility barrier 26 and may push the catheter body 264 in the distaldirection through the distal hub member 24, through the introducersheath 40 and onto the patient's vasculature, thereby causing theflexible sterility barrier 26 to pucker and causing the proximal hubmember 22 and distal hub member 24 to be drawn closer to one another.Both hub members may then be re-taped to the patients skin, therebyholding the catheter body 264 in the presently advanced position.Similarly, if it is later desired to pull the catheter body back to adifferent position, the operator may repeat the above-described process,drawing the catheter in the proximal direction and causing the hubmembers 22, 24 to become further apart from one another.

With particular reference to FIGS. 4 a-4 c, the connector bodies 14, 12are connected to one another by inserting the tubular projections 42, 48into bores 43, 49 of the first connector body 12 and allowing pawls 16 ato snap into detents 16 b, thereby locking the first connector body 12and second connector body 14 together. When it is subsequently desiredto disconnect the catheter, the proximal ends of the pawls 16 a aredepressed causing their opposite ends to disengage from detents 16 b andthe first connector body 12 and second connector body 14 are pulledapart as shown in FIG. 4 a. After the connector bodies 12, 14 have beenseparated, a syringe SYR or other source of negative pressure isattached to tubular projection 48 and used to draw residual fluid out ofthe catheter body 264 and heat exchanger 268, thereby causing heatexchanger 268 to assume a collapsed configuration in which the diameterof the heat exchanger 268 is only slightly larger than the diameter ofthe catheter body 264 adjacent to the heat exchanger 268. The one wayvalve 46, as shown in FIG. 1 a, prevents air from entering thecatheter's closed loop flow circuit though the other tubular projection42 as negative pressure is applied by the syringe SYR. In situationswhere the assembly 10 includes the optional pressure indicator 57, theoperator may continue to withdraw the plunger of the syringe until theoptional pressure indication indicates that the negative pressure withinthe catheter's closed loop flow circuit is sufficient to ensure that thefluid has been adequately removed from the closed loop circuit and/orany expandable portion of the catheter (e.g., balloon, heat exchanger,etc.) has been sufficiently deflated to allow safe movement andwithdrawal of the catheter 260 from the patient's body. In embodimentswhere the assembly 10 further comprises an optional disabling apparatusas described above, this process of evacuating the catheter's closedloop circuit may also cause the optional disabling apparatus topermanently block or impede flow through the catheter's closed loop flowcircuit so that the catheter can not easily be reused.

B. An Endovascular Temperature Control System Incorporating anIntroducer Sheath/Temperature Probe Assembly

Various types of heat exchange catheters and related apparatus may beused in conjunction with the valved connector and sterility barrierassembly 10 to alter and/or control the temperature of all or a portionof the body of a human or veterinary patient. Examples of such heatexchange catheters and related apparatus are described in U.S. Pat. Nos.6,149,676 and 6,149,676 and co-pending U.S. patent applications Ser.Nos. 09/138,830, 09/563,946 and 09/707,257, the entireties of which areexpressly incorporated herein by reference. FIG. 2 shows one particularendovascular heat exchange system 101 which comprises an valvedconnector and sterility barrier assembly 10 of the present invention incombination with a re-usable heater/cooler/control unit 270 and aplurality of disposable components including a heat exchange catheter260, a heat exchange cassette 276, a saline bag or fluid reservoir 278and a plurality of fluid flow conduits including a two-way conduit 265one end of which attaches to the heat exchange cassette 276 and theother end of which terminates in the first connector body 12 of theconnector & sterility barrier assembly 10. Optionally, the system 101may further include one or more additional body temperature probes orsensors 265 a, 265 b.

The re-usable heater/cooler/control unit 270 includes an outer housing284 having a cassette insertion slot 285 into which the heat exchangecassette 276 may be inserted. A heater/cooler 288 such as athermoelectric plate, a pump driver 290, and a microprocessor controller292 are positioned within the housing 284. In addition, a manual inputunit 294 enables an operator to enter desirable operating parametersinto the microprocessor controller 292, for example a pre-selectedtarget body temperature. Each of the electronic devices provided withinthe control unit 270 communicate through suitable wiring or otherconnections. Additionally, wire(s) other connection(s) (e.g., a wirelessconnection or fiber optic connection) connect the body temperaturesensor(s) 265 a, 265 b as well as a heat transfer fluid temperaturesensor and/or flow sensor 275 located on the catheter 260, to themicroprocessor controller 292. Thus, signal(s) indicating the patient'sbody temperature as well as signal(s) indicating the temperature and orflow rate of the heat exchange fluid entering and/or exiting the heatexchange catheter 260 are received by the microprocessor controller 292.

In this example, the microprocessor/controller 292 may receiveindications of a) patient body temperature as sensed by body temperaturesensor(s) 267 a, 267 b, b) temperature and/or flow rate of heat exchangefluid flowing through the closed loop flow circuit of the heat exchangecatheter 260 as sensed by sensor 261 and c) other parameters or targets(e.g., maximum rate of cooling or warming) input by the operator throughthe manual input unit 294. As those of skill in the art will appreciate,other sensed or operator-input parameters or variables may also bereceived by the microprocessor controller 292.

The heat exchange catheter 260 may comprise any suitable type ofcatheter designed to exchange heat with the patients blood, includingthose heat exchange catheters described in U.S. Pat. No. 5,486,208(Ginsburg), PCT International Publication WO OO/10494 (Machold et al.),U.S. Pat. No. 6,264,679 (Keller et al.), PCT International PublicationNos. WO-00/10494 (Radiant Medical, Inc.) and WO 01/58397 (RadiantMedical, Inc.), the entireties of which are expressly incorporatedherein by reference. One presently preferred heat exchange catheter 260for use with this system 101 is shown in FIGS. 2 and 5-7. Thisparticular heat exchange catheter 260 comprises a flexible catheter bodyor catheter shaft 264 and a heat exchange balloon 268. A working lumen271 extends from a proximal port 268 through the catheter shaft 264 andterminates in an opening in the distal end of the catheter shaft 264.This working lumen 271 may be used for passage of a guidewire 273 and/orother optional apparatus, sensors, probes or other devices (e.g,temperature monitoring probes, pH measuring probes, etc.) and/or forinjection/infusion of substances (e.g., radiographic contrast medium,drugs, fluids, etc.). Additionally an inflow lumen 296 extends from theinflow port 297, through the inflow bore of the connector assembly 11,through the catheter shaft 264 and into the interior of the heatexchange balloon 268. A outflow lumen 298 extends from the interior ofthe heat exchange balloon 268, through the catheter shaft 264, throughthe outflow bore of the connector assembly 11 and to the outflow port299.

Two way flow conduit 265 has inflow and outflow lumens (not shown)extending therethrough. Bifurcations are formed on both ends of the twoway flow conduit 265, as shown in FIG. 2. In this manner, the inflowlumen side of the two way flow conduit 265 is connected between theoutflow port 297 of the cassette 276 and the inflow bore of theconnector assembly 11 and the outflow lumen side of the two way flowconduit 265 is connected between the outflow bore of the connectorassembly 11 and the inflow port 275 of the cassette 276.

As shown in FIGS. 5-7, the preferred heat exchange balloon 268 comprisesa multi-lobed structure. The exact number of balloon lobes may varydepending on the particular application for which the heat exchangecatheter 260 is being used and/or the size of the blood vessel in whichthe heat exchange balloon 268 is to be positioned. Preferably the heatexchange balloon 268, when fully inflated, will have a maximum diameterthat is at least slightly smaller than the internal diameter of theblood vessel lumen in which it is positioned, thereby allowing blood toflow freely around the inflated heat exchange balloon 268. In thisexample, the heat exchange balloon 268 comprises four (4) tubular lobes,a central lobe 300 and three (3) outer lobes 302, 304, 306 that arehelically wound about the central lobe 300. As can be seen in FIGS. 5and 6, the catheter shaft 264 extends into and is joined with thecentral lobe 300 of the balloon. As may be appreciated particularly fromthe showings of FIGS. 5A, 5B and 5C and 6, the outflow lumen 298 of thecatheter shaft 264 is connected via outflow slots 310 to the interior ofthe heat exchange balloon 268 such that heat transfer fluid may flowfrom the interior of the heat exchange balloon 268, through outflowslots 310, through outflow lumen 298, though outflow port 299, throughthe outflow lumen of two way conduit 265 and into the interior of theheat exchange cassette 276 through its inflow port 297. As shown inFIGS. 5-7, a medial catheter shaft 264M which includes a continuation ofthe inflow lumen 296 and working lumen 271 extends distally through thecentral lobe 300 of the heat exchange balloon 268 beyond the outflowslots 310 to the distal portion of the balloon where the inflow lumen296 is connected to the interior of the heat exchange balloon 268through inflow slots 312. Thus, a pump 293 mounted within the cassette276 may pump heat transfer fluid from the open inner chamber of thecassette 276, through a convoluted or serpentine flow path defined by aconvoluted or serpentine bulkhead or flow director 273 positioned withinthe cassette 276, through the outflow port 275 of the cassette 276,through the inflow lumen of two way conduit 265, through the inflow port297, through the inflow lumen 296 of catheter shaft 264 and medialcatheter shaft 264M, through inflow slots 312 and into the interior ofthe heat exchange balloon 268. In this manner heat transfer fluid thathas become heated or cooled within the cassette 276 will enter thedistal portion of the heat exchange balloon 268 and circulate generallyin the proximal direction, exiting from the proximal portion of the heatexchange balloon 268.

C. Automated Control of Patient Temperature using the EndovascularTemperature Control System with the Valved Connector & Sterility BarrierAssembly

In typical use, the heat exchange catheter 260 with its heat exchangeballoon 268 in a non-inflated, collapsed state, is percutaneouslyinserted through an introducer 40 as described hereabove and shown inFIGS. 3 a-3 c. The heat exchange catheter 260 is then advanced to aposition wherein the heat exchange balloon 268 is positioned within thepatient's inferior vena cava (IVC) or other desired location.

In some cases, it may be desirable to initially insert the catheter to aposition where the catheter's heat exchanger 268 is thought to beproperly positioned and to subsequently take an x-ray to verify theposition of the heat exchanger 268 and, at that time, the distal hubmember 24 of the sterility barrier assembly 19 is sealed to the hub ofthe introducer 40 and/or covered with a sterile dressing and thesterility barrier 25 protects the portion of the catheter body 260 thatremains exteriorized from contamination. The proximal hub member 22 ofthe sterility barrier assembly 19 may be taped to the patients body tohold the catheter body 264 in substantially fixed longitudinal positionsuch that it will not inadvertently advance or retract. If it isdetermined from the x-ray that the heat exchanger 268 is not optimallypositioned, it may be desirable to free up the proximal hub member 22and move or reposition the catheter 260. In so doing, the operator maygrasp the exteriorized portion of the catheter body 264 through thesterility barrier 26 and retract or advance the catheter body asdescribed above and shown in FIGS. 3 b-3 c.

One or more body temperature sensor(s) 267 a, 267 b as shown in FIG. 2is/are inserted into or positioned on the patient's body to providefeedback of the core body temperature or temperature of a particularbody part. A bag or vessel 278 containing a suitable heat transferfluid, such as sterile 0.9% NaCl solution, is attached to the proximalinflow furcation of the two way flow conduit 265 and the first connectorbody 12 attached to the distal end of the two way flow conduit 265 isconnected with the second connector body 14 such that the distal ends ofthe pawls 16 a of latch 16 snap into the detents 16 b (see FIG. 4 a) onthe second connector body 14, thereby locking the connector bodies 12,14 together, as shown in FIG. 2. The heat transfer fluid is thentransferred from the bag or vessel 278 to fill the cassette 276, bothlumens of the two way flow conduit 265, the connector assembly 11,connector assembly feed and return tube extensions 18 and 20, the inflow296 and outflow 298 lumens of the proximal and medial portions of theheat exchange catheter shaft 264, 264M and the lobes 300, 302, 304, 306of the heat exchange balloon 268. This causes the heat exchange balloonto assume its inflated configuration as shown in FIGS. 5-7. Any largeair bubbles are purged such that the heat transfer fluid within thesystem 101 is substantially free of large air bubbles.

The cassette 276 is inserted into the cassette receiving slot 285 suchthat the cassette is positioned adjacent to the heater/cooler 288 andthe pump driver 290 engages the pump 293. The operator inputs the targetbody temperature into the input apparatus 294. The system 101 is thenenergized and the controller receives the temperature signals from thetemperature sensors 267A, 267B within the probe 32 and compares thesensed temperatures. If the difference between the temperatures sensedby the first sensor 40A and the second sensor 40 B is greater than thepreset allowable difference (e.g., 1 degree difference) the controllerwill issue a warning signal to the operator and/or will automaticallyshut down or prevent start up of the pump driver 290, thereby stoppingor preventing any heat transfer fluid from being circulated through theheat exchange balloon 268. If, on the other hand, the difference betweenthe temperatures sensed by the first sensor 40A and the second sensor 40B is no more than a preset allowable difference (e.g., 1 degree) thecontroller will average the two sensed temperatures and that averagewill be taken as the current measured body temperature to use as the“driver” temperature. Alternatively, the controller may compare the twosignals, and if they are within the predetermined range (e. g. 1 degreeC or 10% or some other appropriate criteria) the controller may ignoreone and use the temperature signal from the other as the temperaturesignal to drive the controller. As yet another alternative, thecontroller may compare the two signals and select one based on someother criteria, for example if the controller is cooling the patient'sbody, the controller may select the cooler of the two temperatures asthe “driver” temperature to use, and thus avoid overcooling the patient,or if the controller is warming, it may select the warmer of the two asthe “driver” temperature signal. If three signals are compared, thecontroller could also use the median temperature signal as the “driver”signal. These and other similar methods of comparing and using multipletemperature signals are all anticipated by this invention.

The controller 292 then compares this current measured body temperatureto the target body temperature that had been entered by the operatorand, if the current measured body temperature is different from thetarget temperature, the controller will cause the heater/cooler toeither heat or cool the heat transfer fluid within the cassette 276and/or will adjust the rate at which the driver 290 drives the pump 293such that the temperature of the heat transfer fluid being circulatedthrough the heat exchange balloon 268 and/or the rate at which the heattransfer fluid is circulated through the heat exchange balloon 268 willcause warming or cooling of the patient's blood until the currentmeasured body temperature reaches the target temperature. The controller292 may be specifically programmed to minimize or prevent overshoot ofthe target temperature as described in U.S. Pat. Nos. 5,837,003(Ginsburg) and 6,149,673 (Ginsburg) and PCT International PatentPublication No. WO-00/10494 (Radiant Medical, Inc.), the entiredisclosures of which are expressly incorporated herein by reference.After the target body temperature has been attained, the controller willcontinuously or periodically predetermine the current measured bodytemperature and will cause corresponding adjustments in theheater/cooler and or pump driver 290 to maintain the patient's bodytemperature at or near the target temperature (e.g., target temperature+or −0.5 degrees C.).

After the procedure is completed, heater/cooler 288 and pump 290 arede-energized. The paws 16 a of latch 16 are depressed and the firstconnector body 12 is separated from the second connector body 14 in themanner depicted in FIG. 4 a. Thereafter, as described in detailhereabove and shown in FIGS. 4 b-4 c, a syringe SYR is attached to theinflow tubular projection 48 and is used to remove heat exchange fluidfrom the catheter 260 and to ensure that the heat exchanger 268 is fullycollapsed before the catheter 260 is withdrawn through the lumen of theintroducer sheath 40 and out of the patient's body. Thereafter, theintroducer sheath 40 may be removed.

While the present invention has been described with reference to thespecific embodiments thereof it should be understood by those skilled inthe art that various changes may be made and equivalents may besubstituted without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particularsituation, material, composition of matter, process, process step orsteps, while remaining within the scope of the present invention.Accordingly, the scope of the invention should therefore be determinedwith reference to the appended claims, along with the full range ofequivalents to which those claims are entitled.

1. A method for connecting a fluid inflow tube and a fluid outflow tube to a closed loop catheter that has a closed loop fluid flow circuit with a first lumen through which a fluid may flow into the catheter and a second lumen through which fluid that has flowed through the first lumen may subsequently flow back out of the catheter, said method comprising the steps of: obtaining a first connector that has an inflow lumen port connected to the inflow tube and an outflow lumen port connected to the outflow tube; and connecting the first connector to a second connector located on the catheter such that the inflow lumen port of the first connector becomes connected to an inflow lumen port of the second connector and the outflow lumen port of the first connector becomes connected to the outflow lumen port of the second connector, whereby fluid from the inflow tube will flow through the inflow lumen of the catheter, through the outflow lumen of the catheter and into the outflow tube.
 2. A method according to claim 1 further comprising the step of disconnecting the first connector from the second connector.
 3. A method according to claim 2 further comprising the step of blocking one of the inflow and outflow lumens when the first connector is disconnected from the second connector such that fluid may then be evacuated from the closed loop flow circuit through the other of the first and second lumens without concurrent entry of make-up air or other fluid into the closed loop circuit.
 4. A method according to claim 3 wherein the step of preventing fluid from entering one of the inflow and outflow lumens is carried out by actuating a valve.
 5. A method according to claim 4 wherein the valve is actuated by the act of disconnecting the first connector from the second connector.
 6. A method according to claim 1 wherein the closed loop catheter comprises a heat exchange catheter through which heat exchange fluid is circulated.
 7. A method according to claim 3 wherein a portion of the closed loop circuit is expandable and contractable such that it contracts when fluid may then be evacuated from the closed loop flow circuit through the other of the first and second lumens without concurrent entry of make-up air or other fluid into the closed loop circuit.
 8. A method according to claim 1 further comprising the step of latching the first connector to the second connector to deter inadvertent disconnection of the connector from the inflow source and outflow receiver.
 9. A method according to claim 1 further comprising the step of determining the pressure of fluid within the closed loop circuit.
 10. A method according to claim 3 further comprising the step of: applying negative pressure to the lumen which remains open to draw remaining fluid from the closed loop circuit.
 11. A method according to claim 10 wherein the step of applying negative pressure comprises attaching a syringe to the lumen that remains open and drawing back the syringe plunger to thereby draw remaining fluid from the closed loop circuit.
 12. A method for maintaining sterility of an exteriorized portion of a catheter that has a closed loop fluid flow circuit with a first lumen through which a fluid may flow into the catheter and a second lumen through which fluid that has flowed through the first lumen may subsequently flow back out of the catheter, said catheter having been inserted into the body of a subject using sterile technique such that the exteriorized portion of the catheter remains outside of the subject's body, said method comprising the steps of: affixing a distal hub of the catheter that is attached to a distal end of a generally tubular sterility barrier to the subject's body at a first location; affixing a proximal hub of the catheter that is attached to a proximal end of the sterility barrier to the subject's body at a second location such that the exteriorized portion of the catheter resides between the first hub and the second hub and within the sterility barrier and is thereby protected from microbial contamination by the sterility barrier.
 13. A method according to claim 12 further comprising the step of adjusting the position of the catheter within the subject's body by: detaching the distal hub from the subject's body; advancing a portion of the exteriorized portion of the catheter through the tubular sterility barrier and into the subject's body, thereby causing the length of the exteriorized portion of the catheter to become shorter; and re-affixing the distal hub to the subject's body.
 14. A method according to claim 13 wherein the tubular sterility barrier is flexible and has an outer surface and wherein the step of advancing a portion of the exteriorized portion of the catheter through the tubular sterility barrier and into the subject's body is carried out by: placing a hand on the outer surface of the tubular sterility barrier; and grasping the exteriorized portion of the catheter while it remains within the tubular sterility barrier.
 15. A method according to claim 12 wherein the generally tubular sterility barrier is substantially transparent and wherein the method further comprises the step of viewing the exteriorized portion of the catheter body through the sterility barrier.
 16. A method according to claim 15 wherein graduated distance markings are formed on the exteriorized portion of the catheter and wherein said graduated distance markings are viewed through the transparent sterility barrier to determine the approximate length of the catheter body that has been inserted into the subject's body. 